South Africa’s blood supply appears to be just as safe from HIV as blood transfusion systems in Europe and North America owing to stringent testing protocols, according to Dr Sam Gulube of the National Blood Service, speaking at the Third South African AIDS Conference in Durban.
However, South Africa faces a growing shortage of blood because the rate of hospital based transfusion is rising, due to the need to correct HIV-related anaemia prior to antiretroviral treatment by giving blood transfusions.
Dr Gulube urged all people who know that they are HIV-negative to give blood regularly.
“Quarterly blood donations mean quarterly HIV testing, but regular donors need to change their behaviour too. If you have had unprotected sex in the past 14 days, don’t donate,” he said.
South Africa’s blood service carries out antibody testing on all samples, and also nucleic acid testing for HIV’s viral material in order to detect blood donations from people who have been recently infected and who don’t yet have antibodies to HIV.
Even though nucleic acid based testing can detect HIV in the blood soon after infection, a window period of 14 days is still recommended by the blood service to be on the safe side.
Dr Gulube reported that between 2001 and 2005, when the service used antibody testing and a test for HIV p24 antigen to screen samples, eight cases of transfusion-associated infection from six donors occurred. Tracing of donors proved that all the donors were in the window period before they had formed HIV antibodies.
The incidence of transfusion-associated infection was 1.8 cases per million units of blood donated, compared with 1.5 cases per million in Europe and an estimate that 5-10% of infections may occur through HIV-infected blood in some developing countries.
The growing blood shortage in South Africa was also highlighted.
“Most people assume that the majority of blood donations are for emergency cases, accidents, because that’s what we hear in the media. In fact only 4% of blood donations go to casualty departments,” said Dr Gulube.
Twenty-six per cent of blood donations go to provide transfusions for patients with chronic medical conditions, and the blood service noted a growing demand for transfusions in 2006.
The demand is being driven, says Dr Gulube, by the need to correct HIV-related anaemia before patients can begin antiretroviral therapy.
“At one time people with a haemoglobin of 6 or 7 would have been sent home, but now if they are eligible for antiretrovirals they need transfusion before they can start,” he told the conference.
Pre-existing anaemia is a particular barrier to starting treatment with AZT (zidovudine) since the antiretroviral drug can worsen pre-existing anaemia.